AU2003222802B2 - The use of hydroxypyridone-derivatives in wound healing - Google Patents

Abstract

The present invention relates to the use of compounds of the formula I, <CHEM> in which R<1>; R<2>; R<3> and R<4> have the meanings indicated in the claims, for the treatment of wounds.

Description

WO 03/088966 PCT/EP03/03618 The use of hydroxypyridone-derivatives in wound healing The present invention relates to the use of compounds of the formula I, R2 1 3 R R R4 N 0

OH

in which R 1

R

2

R

3 and R 4 have the meanings indicated below, in wound healing.

Compounds of formula I such as 6-Cyclohexyl-1-hydroxy-4-methyl-2(1H)-pyridone 2aminoethanol salt, also known as ciclopirox olamine (CPX) are widespread anti-fungal agents used to treat mycoses of the skin and nails since more than 20 years. Apart from its antimycotic activity, CPX is also effective against both gram-positive and gram-negative bacteria (Dittmar, W. et al.(1981) Microbiological laboratory studies with ciclopiroxolamine.

Arzneimittelforschung 31, 1317-1322). CPX is applied as a 1 cream or gel to treat dermatomycoses and as a 8% nail lacquer to treat onychomycoses. CPX is known to inhibit diverse fungal enzymatic activities in microorganisms, including the transmembrane transport of amino acids, potassium and phosphate. However, the general molecular mechanism of the anti-microbial activity of CPX is not exactly known.

In studies addressing the cutaneous effects of a 1% CPX solution applied on rabbit skin over days, occasionally transient reddening of healthy skin and persistent reddening of experimentally wounded skin has been observed (Alpermann, H. and SchUtz, E. (1981) Studies on the pharmacology and toxicology of ciclopiroxolamine. Arzneimittelforschung 31, 1328-1332). Occasionally transient reddening of healthy skin was explained as a side reaction of CPX.

Therapeutic angiogenesis by recombinant angiogenic growth factors or by gene therapy has become an important treatment modality during the past few years (Hockel, M. et al. (1993) Therapeutic angiogenesis. Arch. Surg 128, 423-429). In ongoing human clinical trials, VEGF gene therapy is applied for the treatment of critical limb ischemia and myocardial ischemia. VEGF therapy has also been experimentally investigated in gastric and duodenal ulceration, as well as in dermal ulcers and in cultured skin substitutes.

It has now been found that the compounds of the formula I Have a potent 00 0o angiogenic activity and induce angiogenesis as evidenced by numerous newly Sformed arranged vessels.

Additionally, it has been found that topic application of CPX does not lead Sto gross systemic alterations in VEGF expression, which limits its function to regions of topical application. This is rather safe and highly advantageous compared to gene therapy. Thus, the compounds of the formula I can be used for the treatment of wounds and/or wound healing, because the potent angiogenic activity differs considerably from the known anti-microbial actitivty of the compounds of the formula I. Thus, not only infections are prevented during the treatment of wounds, but also wound healing is improved by e.g. forming of numerous new vessels in and around the wound.

The invention therefore relates to the use of 1-hydroxy-2-pyridones of the formula 1 R2 RbR

(I)

4 R N 0

OH

for the preparation of a pharmaceutical for wound healing, wherein the wounds are abrasions, burns, chaps, crush wounds, cuts, diabetic foot ulcers, gaping wounds, gashs, grafting of organs, gunshot wounds, incisions, scorch wounds, scratches, skin bums, sores, squeeze wounds, stab wounds, transplantation, venous ulcers or wounds due to surgery or plastic surgery, 0 wherein the compound of the formula I is administered topically in the form of

O

c emulsions, ointments, solutions, tinctures, powders, cream or gel preparation or in the form of aerosols or foams, in which R 1

R

2 and R 3 are identical or different and are a hydrogen atom or alkyl 0 5 having 1-4 carbons atoms, and

R

4 is a saturated hydrocarbon radical having 6 to 9 carbon atoms or a radical of Sthe formula II 00 (N Ar-Z--

Y

where X is S or O, Y is a hydrogen atom or up to 2 halogen atoms such as chlorine and/or bromine, Z is a single bond or the divalent radical comprising a) or b) S, or c) -C(R 5

)(R

6 wherein R 5 and R 6 are identical or different and are independently hydrogen atom or (Cl-C 4 )-alkyl; or d) other divalent radicals having 2 to 10 carbon in the form of a chain, which optionally further comprises one or more of the following: i) a carbon-carbon double bond, or ii) O, S, or a moisture thereof, wherein if 2 or more O and/or S atoms or a mixture thereof are present, each O or S atom is separated by at least 2 carbon atoms; and, In any of the foregoing bivalent radicals, the free valences of the carbon atoms of said bivalent radical are saturated by a hydrogen atom, (C1-C4)alkyl, or a mixture thereof; and Ar is an aromatic ring system having up to two rings which can be substituted by up to three radicals from the group consisting of fluorine, chlorine, bromine, methoxy, (C 1

-C

4 )-alkyl, trifluoromethyl and trifluoromethoxy in free or in salt form.

The invention also relates to a method for wound healing in an animal, wherein the wounds are selected from the group consisting of: crush wounds, cuts, gunshot wounds, incisions, squeeze wounds, stab wounds and wounds due to surgery or plastic surgery, which method comprises administering topically to the animal in the form selected from the group consisting of: emulsions, ointments, solutions, tinctures, powders, aerosols, foams, cream and gels, 1-hydroxy-2-pyridones compounds of the formula 1 in which R 1

R

2 and R 3 are identical or different and are a hydrogen atom or alkyl having 1-4 carbons atoms, and

R

4 is a saturated hydrocarbon radical having 6 to 9 carbon atoms or a radical of the formula II Ar-Z x- -CH 2 where X is S or O, Y is a hydrogen atom or up 2 halogen atoms such as chlorine and/or bromine, Z is a single bond or the divalent radical comprising: a) O, or b) S, or c) -C(R 5

)(R

6 wherein R 5 and R 6 are identical or different and are independently hydrogen atom or (C 1

-C

4 )-alkyl; or d) other divalent radicals having 2 to 10 carbon in the form of a chain, which optionally further comprises one or more of the following: i) a carbon-carbon double bond, or ii) O, S, or a moisture thereof, wherein if 2 or more O and/or S atoms or a mixture thereof are present, each O or S atom is separated by at least 2 carbon atoms; and, in any of the foregoing bivalent radicals, the free valences of the carbon atoms of said bivalent radical are saturated by a hydrogen atom, (C 1

-C

4 )-alkyl, or a mixture c thereof; and o 0 Ar is an aromatic ring system having up to two rings which can be (substituted by up to three radicals from the group consisting of fluorine, chlorine, 10 bromine, methoxy, (C 1

-C

4 )-alkyl, trifluoromethyl and trifluoromethoxy in free or in C- salt form The radical denotes a sulphur atom; the radical denotes an oxygen atom. The term "Ar" denotes phenyl or condensed systems such as naphthyl, tetrahydronaphthyl and indenyl, and also isolated systems such as those, which are derived from biphenyl, diphenylalkanes, diphenyl ethers and diphenyl thioethers.

WO 03/088966 WO 03/88966PCT/EP03/03618 4 The term "saturated hydrocarbon radical having 6 to 9 carbon atoms" means that the radical can be straight-chain, branched or cyclic and contains no aliphatic multiple bonds, i.e. no ethylenic or acetylenic bonds. Examples of the R 4 radical are e.g. hexyl, heptyl, octyl, cyclohexyl or cycloheptyl.

The hydrocarbon radical R 4 in the compound of formula I is preferably an -(C-C 8 )-alkyl or cyclohexyl radical, which may also be linked via a methylene or ethylene group to the pyridone ring or can contain an endomethyl group. R4can also be an aromatic radcical which,,however, is preferably bonded to the pyridone radic'al via at least one aliphatic carbon atom.

Important representatives of the class of compound characterised by the formula I are: 6-[4(4ch lorop henoxy)p henoxymethyI-1 -hyd roxy-4-methyl-2-pyrid one, ich Ilorophenoxy) phen oxymethyl-1 -hyd roxy-4-methyl-2-pyrid one, 6-(b iph enylyl1-4-oxymethyl)-1 -hyd roxy-4-m ethyl -2-pyri done, 6-(4-benzyl-phenoxymethyl)-1 -hydroxy-4-methyl-2-pyridone, ich loro-benzyloxy)phenoxymethyl]-1 -hyd roxy-4- methyl -2-pyri done, 6-[4-(4-chlo rop hen oxy)p hen oxyl ethyl]-1 -hydroxy-3,4-di methyl-2-pyridone, ich Ioro benzyl) ph enoxym ethyII-1 hyd roxy-3,4-d im ethyl -2-pyri done, 6-[4-(cin namyloxy)phenoxymethyl]-1 -hydroxy-4-methyl-2-pyridone, 1 -hyd roxy-4-m ethyl [4-(4-triflI u oromethyl phen oxy) ph enoxymethyl-2- pyri done, 1 -hyd roxy-4- methyl -6-cycl oh exyl-2-pyrid one, 1 hyd roxy-4- methylI-6-(2,4,4-t rim ethyl pentyl)-2-p.yrid one, 1 .hydroxy-4-methyl-6-n-hexyl-, -6-iso-hexyl-, -6-n-heptyl- or -6-iso-heptyl-2-pyridone, 1 -hydroxy-4-methyl-6-octyl- or -6-iso-octyl-2-pyridone, in particular 1 -hydroxy-4-methyl-6cyclohexyl-methyl- or -6-cyclohexylethyl-2-pyridone, where the cyclohexyl radical in each case can also carry a methyl radical, 1 -hydroxy-4-methyl-6-(2-bicyclo!I2,2,1]heptyl)-2-pyridone, '1-hyd roxy-3,4-d imethyl-6-benzyI- or -6-dimethylbenzyl-2-pyridone or 1 -hyd roxy-4-methy-6-(B-phenylethyl)-2-pyridone.

WO 03/088966 PCT/EP03/03618 The above-mentioned compounds of the formula I can be employed both in free form and as salts; use in free form is preferred.

If organic bases are used, poorly volatile bases are preferably employed, for example low molecular weight alkanolamines such as ethanolamine, diethanolamine, Nethylethanolamine, N-methyldiethanolamine, triethanolamine, diethylaminoethanol, 2amino-2-methyl-n-propanol, dimethylaminopropanol, 2-amino-2-rmethylpropanediol, triisopropanolamine. Further poorly volatile bases which may be mentioned are, for example, ethylenediamaine, hexamethylenediamine, morpholine, piperidine, piperazine, cyclohexylamine, tributylamine, dodecylamine, N,N-dimethyldodecylamine, stearylamine, oleylamine, benzylamine, dibenzylamine, N-ethylbenzylamine, dimethylstearylamine, N-methylmorpholine, N-methylpiperazine, 4-methylcyclohexylamine, N-hydroxyethylmorpholine. The salts of quaternary ammonium hydroxides such as trimethylbenzylammonium hydroxide, tetramethylammonium hydroxide or tetraethylammonium hydroxide can also be used, and furthermore guanidine and its derivatives, in particular its alkylation products. However, it is also possible to employ, for example, low molecular alkylamines such as methylamine, ethylamine or triethylamine as saltforming agents. Salts with inorganic cations, for example alkali metal salts, in particular sodium, potassium or ammonium salts, alkaline earth metal salts such as in particular the magnesium or calcium salts, and salts with di- to tetravalent cations, for example the zinc, aluminium or zirconium salt, are also suitable for the compounds to be employed according to the invention.

The compounds of the formula I can be prepared, for example, by the process according to US 2 540 218 or US 4 797 409.

The present invention also relates to the use of the compound of the formula I, in which Ar is a bicyclic system, which is derived from biphenyl, diphenylalkane or diphenyl ether.

The present invention also relates to the use of the compound of the formula I, which contains a cyclohexyl radical in the position R 4 WO 03/088966 PCT/EP03/03618 6 The present invention also relates to the use of the compound of the formula I, which contains an octyl radical of the formula -CH 2 -CH(CH3)-CH2-C(CH3)3 in the position R 4 The present invention also relates to the use of the compound of the formula I, wherein 1-hydroxy-4-methyl-6-[4-(4-chlorophenoxy)phenoxymethyl]-2-(1H)pyridone, 1-hydroxy-4methyl-6-cyclohexyl-2-(1H)pyridone or 1-hydroxy-4-methyl-6-(2,4,4-trimethylpentyl)-2- (1H)pyridone is employed.

The present invention also relates to the use of the compounds of the formula I for the production of a pharmaceutical for the treatment of wounds.

Due to the induction of angiogenesis the healing of wounds is improved, because new blood vessels are formed and the supply of the wound with nutrition and oxygen is improved. Thus, also wound healing of uninfected wounds is dramatically increased. The compounds of the formula I do not only prevent infections of the wound by e.g. yeast, bacteria or fungi, but also support wound healing by a better supply of the wound by the induction of newly formed blood vessels. Thus, wound healing of un-infected and infected wounds is improved by the treatment of the compounds of the formula I.

The term "wounds" is understood as meaning e.g. abrasions, burns, chaps, crush wounds, cuts, diabetic foot ulcers, gaping wounds, gashs, grafting of organs, gunshot wounds, incisions, leg ulcers, pressure ulcers, scorch wounds, scratches, skin burns, sores, squeeze wounds, stab wounds, transplantation, venous ulcers or wounds due to surgery or plastic surgery.

The term "wound healing" is understood as meaning regenerative processes for the closing of a wound; especially new forming of capillary vessels and increase of connective tissue and epithelial cells.

The compounds of the formula I and their physiologically tolerable salts can be administered to animals, preferably to mammals, and in particular to humans as pharmaceuticals for the treatment of wounds and/or wound healing. They can be administered on their own, or in mixtures with one another or in the form of pharmaceutical preparations, which permit topical administration. The term "mammals" is understood as meaning e.g. human, horse, cattle, pig, rat, mouse, sheep or dog.

WO 03/088966 PCT/EP03/03618 7 The pharmaceuticals can be administered percutaneously or topically, for example in the form of emulsions, ointments, solutions or tinctures, powders, or in other ways, for example in the form of aerosols or foams. For use according to the invention of the compounds mentioned, liquid, semisolid and solid pharmaceutical preparations are suitable, in particular solutions, cream, ointment, powders and gel preparations, where the latter are preferably used because of their increased release of active compound.

The pharmaceutical preparations according to the invention are prepared in a manner known per se and familiar to one skilled in the art, pharmaceutically acceptable inert inorganic and/or organic carriers being used in addition to the compound(s) of the formula I and/or its (their) physiologically tolerable salts.

The compounds of the formula I can also be incorporated in or on surgical gauze, bandage or dressing.

Suitable dressings are illustrated in more detail by the following examples: Alginate dressings Alginate wound dressings are woven from calcium alginate fibers. Calcium alginate is a marine biopolymer that is derived from seaweed. Alginates are highly absorptive. When the alginates dressing comes into contact with wound exudate, a soft gel is formed, maintaining a moist environment at the wound surface that is conducive to the formation of granulation tissue and epithelialization. Alginate dressings are indicated for heavily exudating wounds, as they have the capacity to absorb as much as 20 times their weight.

Composite dressings They are generally multi-layered, incorporating a nonadherent layer that is in contact with the wound, and various absorbent, wicking, and semi-occlusive layers. The absorptive layer does not incorporate a foam, alginate, hydrocolloid, or hydrogel. A nonwoven adhesive tape backing secures the dressing to the skin. These dressings are used as cover dressings for all phases of wound healing and are primary dressing for many types of post-operative wounds.

WO 03/088966 PCT/EP03/03618 Contact layers Contact layers are thin sheet dressings placed directly on an open wound to protect the wound tissue from direct contact with other agents or dressings applied to the wound. Secondary dressings are always used with contact layers.

Foam dressings Foam dressings are made primarily from polyurethane, but silicone is also used. They are available as either flat foam dressings or as fillers, and are intended for use on granulation and epithelializing wounds producing some exudate.

Gauze Woven gauze dressings are made from 100% cotton yarn. The threads are horizontally and vertically woven, with 10 to 20 separate manufacturing steps employed in the process of producing a 4 x 4 inch, 12-ply sponge. Woven gauze dressings come in a wide range of types and are commonly used for packing and debridement.

Nonwoven fabrics are neither woven nor knitted. The fibers are arranged such that they appear to be woven. Most nonwoven dressings are manufactured from a blend of rayon and polyester. Rayon provides softness and absorbency, while polyester provides strength. The primary application of nonwoven gauze dressings is for absorption and wrapping.

Impregnated gauze dressings Impregnated gauze dressings are woven or nonwoven materials in which substances have been incorporated into the dressing material.

Hydrocolloid dressings Hydrocolloid dressings are popular second-generation dressings, which are moderate absorptive, moisture-retentive, conformable to the wound, and self-adhesive. They are also occlusive, forming a barrier against bacterial contamination. In addition to being available in dimensional forms, hydrocolloids are supplied as powders, granules, pastes, and other specialised forms. The major functional components are gelatine, pectin, or related hydrocolloids. They are indicated for use on pressure ulcers, burns, and a variety of other wound types.

WO 03/088966 PCT/EP03/03618 9 Hydrogel dressings Hydrogels are semipermeable dressings of which water is the major component.

Glycerine or propylene glycol are included as humectants, and a co-polymer starch is sometimes added as absorptive. The dressings are available as gauze-impregnated wafers, sheets, and amorphous gels, and are indicated for partial- and full-thickness wounds nondraining to moderately draining.

Transparent film dressings Transparent film dressings are occlusive dressings consisting of a polyurethane membrane framed by an adhesive layer. The dressings vary in thickness, degree of occlusiveness, and other properties. Transparent film dressings are indicated for use on small surgical incisions, insertion points for peripheral and central venous catheters, superficial burns, partialthickness breakdown wounds, and as secondary dressings.

Biological and biosynthetic dressings This sector includes -a group of naturally absorptive and biological compatible collagen-based dressings -dressings constructed of related biocompatible amino acids and protein hydrolysates -dressings which combine synthetic and biologically derived materials The compounds of the formula I can be topically administered to human and other mammals such as dog, cat, horse, pig, cattle or sheep.

The pharmaceutical preparations normally contain from about 0.05 to about 5 preferably from 0.5 to 2 especially preferably by weight of the compounds of the formula I and/or their physiologically tolerable salts. Smaller and higher percentages are also possible.

In addition to the active ingredients of the formula I and/or their physiologically acceptable salts and to carrier substances, the pharmaceutical preparations can contain additives such as, for example, fillers, binders, lubricants, wetting agents, stabilizers, emulsifiers, preservatives, colorants, thickeners, diluents, buffer substances, solvents, solubilizers, agents for achieving a depot effect, salts for altering the osmotic pressure, coating agents or antioxidants. They can also contain two or more compounds of the formula I and/or their physiologically tolerable WO 03/088966 PCT/EP03/03618 salts. Furthermore, in addition to at least one compound of the formula I and/or its physiologically tolerable salts, the pharmaceutical preparations can also contain one or more other therapeutically or prophylactically active ingredients. Such additional active ingredients can be dexpanthenol, allantoin, dextranomer, and/or extracts of the Echinacea plant.

It is understood that changes that do not substantially affect the activity of the various embodiments of this invention are included within the invention disclosed herein. Thus, the following examples are intended to illustrate but not limit the present invention.

Example 1 Induction of VEGF gene expression by CPX Methods Cell culture The HRCH05 cells containing a stable transfected, HIF-1-dependent reporter gene were described previously (Wanner, R. et al. (2000) Epolones induce erythropoietin expression via hypoxia-inducible factor-la activation. Blood 96, 1558-1565). The human HepG2 hepatoma cell line was obtained from American Type Culture Collection (ATCC numbers HB-8065). All cell lines were cultured in Dulbecco's modified Eagle's medium (DMEM, high glucose, Life Technologies) supplemented with 10% heat-inactivated FCS, 100 U/ml penicillin, 100/ g/ml streptomycin, 1 x non-essential amino acids and 1 mM Na-pyruvate (all purchased from Life Technologies) in a humidified atmosphere containing 5% C02 at 37 0 C. Oxygen partial pressures in the incubator (Forma Scientific, model 3131) were either 140 mm Hg (20% Oz v/v, normoxia) or 7 mm Hg O2 v/v, hypoxia). Ciclopirox olamine (CPX), deferoxamine mesylate (DFX) and 2,2'-dipyridyl (DP) were purchased from Sigma. Stock solutions of CPX and DP were prepared in methanol at 0.5 M and 1 M, respectively. DFX was freshly dissolved at 10 mM into the cell culture medium.

Transient transfection, reporter gene and viability assays WO 03/088966 PCT/EP03/03618 11 HepG2 cells were transiently electroporated with a VEGF promoter-driven luciferase construct as described previously (Ikeda, et al. (1995) Hypoxia-induced transcriptional activation and increased mRNA stability of vascular endothelial growth factor in C6 glioma cells. J. Biol. Chem.

270, 19761-19766). Following stimulation, transiently and stable transfected cells were lysed in passive lysis buffer (Promega) and the luciferase activity was determined using a luciferase assay kit according to the manufacturer's instructions (Promega) in a 96-well luminometer (MicroLumat LB96P, EG&G Berthold). Cell proliferation/viability was assessed by the 3-(4,5dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay as described (30, 31).

Absorbances at 570 nm were determined in a 96-well photometer (Rainbow, SLT Labsystems).

Results CPX in a concentration from 5pM to 20/pM concentrations strongly induced the HIF-1 a protein in normoxic HepG2 hepatoma cells after 6 and 24 hours of treatment. While no HIF-la protein could be detected in normoxic cells, hypoxia 02) also strongly induced HIF-la. The combination of CPX and hypoxia did not further increase HIF-la levels after 6 hours but rather decreased HIF-la levels after 24 hours of treatment.

As determined by Northern blotting of mRNA derived from HepG2 cells treated with CPX, DFX and DP for 24, 48 and 72 hours, these iron chelators also induced the expression of the endogenous HIF-1 target genes VEGF, glucose transporter-1 (Glut-1) and aldolase but not of the control genes L28 and p-actin.

The functionality of CPX-induced VEGF mRNA expression was further demonstrated by the accumulation of VEGF protein in the supernatant of the HepG2 cell culture, which increased in a dose-dependent manner following 6 or 24 hours of treatment.

A luciferase reporter gene driven by a 1180 bp VEGF promoter fragment was transiently transfected into HepG2 cells, which were split and treated with increasing concentrations of CPX for 24 hours. A dose-dependent increase in luciferase activity was observed, suggesting that CPX transcriptionally activates VEGF expression. In summary, these results demonstrate WO 03/088966 PCT/EP03/03618 12 that CPX can activate endogenous VEGF transcription, mRNA expression and secreted protein accumulation.

Example 2 Lack of HIF-1 target gene induction by CPX in the isolated perfused rat kidney Systemically administered DFX can induce ubiquitous HIF-1 stability and kidney-specific erythropoietin expression in mice (Wang, G. and Semenza, G. L. (1993) Desferrioxamine induces erythropoietin gene expression and hypoxia-inducible factor 1 DNA-binding activity: implications for models of hypoxia signal transduction. Blood 82, 3610-3615). Regarding a topical application of CPX as a HIF-1-inducing agent for therapeutic angiogenesis, itwas important to test whether CPX could lead to a systemic induction of VEGF. As an ex vivo model, isolated rat kidneys were perfused for 3 hours under normoxic conditions with increasing concentrations of CPX. However, CPX did not induce the mRNA levels of the HIF-1 target genes VEGF, Glut-1 or aldolase at concentrations ranging from 0.1 pM to 100 pM. The higher CPX concentrations (33 pM and 100 pM) led to a down regulation of kidney function as indicated by a strong increase in the albumin and sodium excretion rates. Following perfusion with 3% oxygen for 3 hours, an increase in Glut-1 but not in VEGF and aldolase mRNA levels was observed which was not further elevated by CPX.

Example 3 Induction of angiogenesis in the chicken chorioallantoic membrane (CAM) by CPX Chick embryo chorioallantoic membrane (CAM) assay Method CAM assays were performed as described by Olivo, M. et al. (A comparative study on the effects of tumor necrosis factor-a (TNF-a), human angiogenic factor (h-AF) and basic fibroblast growth factor (bFGF) on the chorioallantoic membrane of the chick embryo, (1992). Anat. Rec. 234, 105-115). Briefly, fertilized eggs (purchased from Lohmann Tierzucht, Cuxhaven, Germany) were incubated at 37 °C in a humidified atmosphere. The eggs were kept on their sides and turned upside down twice a day. After 6 days, a small hole was drilled through the shell into the air sac (visualized using a strong light source) and a window of approximately 0.5 cm 2 was WO 03/088966 PCT/EP03/03618 13 sawed into the side of the egg. The window was sealed with tape and the eggs were reincubated until day 9, when 6-Cyclohexyl-1-hydroxy-4-methyl-2(1H)-pyridone 2aminoethanol salt (CPX) was applied to the CAM using the Elvax" method (see Olivo, M. et al.

above). Therefore, ethylene/vinyl acetate copolymer beads (Elvax' 40L-03, DuPont, provided by C. H. Erbslih KG, Krefeld, Germany) were extensively washed in ethanol and dried under reduced pressure. The Elvax" beads were then dissolved in methylene chloride at 10% and CPX was added to the desired concentration. One drop (40/pL) of this solution was pipetted onto a siliconized glass slide and the solvent was allowed to evaporate completely. Using forceps, the Elvax' disc was carefully lifted from the glass slides and placed onto the CAM. At day 11, the window was enlarged and the CAM was documented using a digital camera (Olympus) coupled to an ocular of a stereomicroscope.

Result Based on the observations that CPX induced VEGF expression in cell culture (see example 1), the angiogenic capacity in an in vivo model of angiogenesis was analyzed. Therefore, the chicken CAM at day 9 of development was overlayed with inert polymer discs containing various concentrations of CPX or solvent only. After two days of incubation, no signs of angiogenesis could be observed with the solvent control discs. In contrast, polymer discs containing 50 mM CPX consistently induced CAM angiogenesis as evidenced by numerous newly formed, radially arranged vessels. A total of 10 CAMs treated with 50 mM CPX showed similar angiogenesis, while all 7 control CAMs lacked any signs of angiogenesis. 5 mM CPX was indistinguishable from the controls and 500 mM CPX was toxic to the chick embryo.

Example 4 Mouse skin wound model Method Both ears of adult NMRI mice were wounded under anesthesia with 100 mg/kg Ketamine (Narketan") and 5 mg/kg Xylazine (Rompun") by punch-through holes of 2 mm diameter using a standard ear-punching tool. The ears were treated daily with a common skin cream containing (Batrafen") or not containing 1% (wlv) CPX. One ear was treated with CPX and the Sother ear with the control cream. The amount of cream was sufficient to cover the C hole and was equally distributed over the entire ear.

Result

\O

CPX can induce angiogenesis in a mouse skin wound model Punch-through ear holes of 2 mm diameter (a widespread way of marking mice in 00 Sanimal facilities) were treated daily with a commercially available dermal cream C- containing 1% CPX on one ear and a CPX-free but otherwise identical common tc, dermal cream on the other ear, respectively. CPX can cause reddening of the c wound margin, which was never observed on the healthy skin area of the same ear. In this series 4 of 10 animals showed similar effects and none of the animals had more pronounced reddening on the placebo-treated wound margin than on the CPX-treated wound margin. The reddening induced by CPX might be enhanced vessel growth.

Comprises/comprising and grammatical variations thereof when used in this specification are to be taken to specify the presence of stated features, integers, steps or components or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

Claims (12)

1. 2. The use as claimed in claim 1, wherein Ar in the compound of the formula I is a bicyclic system, which is derived from the group consisting of: biphenyl, diphenylalkane and diphenyl ether.
2. 3. The use as claimed in claim 1, wherein the compound of formula I contains a cyclohexyl radical in the position R 4
3. 4. The use as claimed in claim 1, wherein the compound of formula I contains an octyl radical of the formula -CH 2 -CH(CH 3 )-CH 2 -C(CH 3 3 in the position R 4 The use as claimed in claim 1, wherein the compound of formula I is 1- hydroxy-4-methyl-6-[4-(4-chlorophenoxy)phenoxymethyl]-2-(1 H)pyridone, 1- hydroxy-4-methyl-6-cyclohexyl-2-(1 H)pyridone or 1-hydroxy-4-methyl-6-(2,4,4- trimethylpentyl)-2-(1 H)pyridine.
4. 6. The use as claimed in any one of claims 1 to 5, wherein any one or more of the compounds of formula I are administered alone or in mixtures thereof.
5. 7. The use as claimed in any one of claims 1 to 5, wherein the dose of the C compound of formula I in the pharmaceutical preparation is from about 0.05% to o about by weight of the compound of the formula I and/or their physiologically tolerable salts. \O
6. 8. The use as claimed in claim 7, wherein the dose of the compound of c formula I in the pharmaceutical compound is 0.05% to about 2% by weight. o00 (N N 9. The use as claimed in claim 7, wherein the dose of the compound of q formula I in the pharmaceutical compound is about 1% by weight. The use as claimed in claim 1, wherein the pharmaceutical preparation contains in addition an active ingredient.
7. 11. The use as claimed in claim 10 wherein the active ingredient is selected from dexpanthenol, allantoin, dextranomer, extracts of the Echinacea plant and a mixture of said ingredients.
8. 12. A method for wound healing in an animal, wherein the wounds are selected from the group consisting of: crush wounds, cuts, gunshot wounds, incisions, squeeze wounds, stab wounds and wounds due to surgery or plastic surgery, which method comprises administering topically to the animal in the form selected from the group consisting of: emulsions, ointments, solutions, tinctures, powders, aerosols, foams, cream and gels, 1-hydroxy-2-pyridones compounds of the formula 1 R2 R R 3 RR(I) 4 R N 0 OH in which R 1 R 2 and R 3 are identical or different and are a hydrogen atom or alkyl having 1-4 carbons atoms, and SR 4 is a saturated hydrocarbon radical having 6 to 9 carbon atoms or a radical of C the formula II C-I Y Z is a single bond or the divalent radical comprising: a) O, or c) -C(R 5 )(R 6 wherein R 5 and R 6 are identical or different and are or a moisture thereof, wherein if 2 or more wher and/or S atoms or a mixture thereof are present, each 0 or S atom is separated by at least X is S or O, 2 carbon a hydrogen atom or up 2 halogen atoms such as chlorine and/or bromine, Z is a single bond or the foregoing bivalent radicals, the free valences of the carbon atoms of a) O, or b) S, or c) wherein R 5 and R 6 are identical or different and are independ bivalent radical are saturated by a hydrogen atom or (C-C4)-alkyl or a mixture thereof; and Ar is an aromatic ring system having 2 to 10 carbon in the form of a chain,tuted which optionally further cals fromprises one group consisre of the followine, chlorine, bromine, i) a carbon-carbon double bond, or methoxy, (CC)aky, trifluor a moisturethyl and trifluoromethoxy f, wherein if 2 or mor in salt for S atoms or a mixture thereof are presentin claim 12, each or S atom is separated by at least 2 carbon atoms; and, in any of the foregoing bivalent radicals, the free valences of the carbon atoms of said bivalent radical are saturated by a hydrogen atom, (C1-C4)-alkyl, or a mixture thereof; and Ar is an aromatic ring system having up to two rings which can be substituted by up to three radicals from the group consisting of fluorine, chlorine, bromine, methoxy, (C1-C4)-alkyl, trifluoromethyl and trifluoromethoxy in free or in salt form.
9. 13. The method as claimed in claim 12, wherein Ar in the compound of the formula I is a bicyclic system, which is derived from the group consisting of: biphenyl, diphenylalkane and diphenyl ether. O 14. The method as claimed in claim 12, wherein compound of formula I CN contains a cyclohexyl radical in the position R 4 The method as claimed in claim 12, wherein the compound of formula I Scontains an octyl radical of the formula -CH 2 -CH(CH 3 )-CH 2 -C(CH 3 3 in the position R 4 00 16. The method as claimed in claim 12, wherein the compound of formula I is 1- c hydroxy-4-methyl-6-[4-(4-chlorophenoxy)phenoxymethyl]-2-(1 H)pyridone, 1- rn hydroxy-4-methyl-6-cyclohexyl-2-(1 H)pyridone or 1-hydroxy-4-methyl-6-(2,4,4- O trimethylpentyl)-2-(1 H)pyridine.
10. 17. The method as claimed in any one of 12 to 16, wherein any one or more of the compounds of formula I are administered alone or in mixtures thereof.
11. 18. The method as claimed in any one of claims 12 to 16, wherein the dose of the compounds of formula I in the pharmaceutical preparation is from about 0.05% to about by weight of the compound of the formula I and/or their physiologically tolerable salts.
12. 19. The method as claimed in any one of claims 12 to 18, wherein the compounds are administered in the form of a pharmaceutical compound together with an active ingredient. The method as claimed in claim 19 wherein the active ingredient is selected from dexpanthenol, allantoin, dextranomer, extracts of the Echinacea plant and a mixture of said ingredients. AVENTIS PHARMA DEUTSCHLAND GMBH WATERMARK PATENT TRADE MARK ATTORNEYS P24607AU00